A multi-band composite photodetector based on a Bayer model and a preparation method thereof

Abstract

The application discloses a multi-band composite photodetector based on a Bayer model and a preparation method thereof, realizes independent detection and signal composition of ultraviolet, visible and near-infrared bands, is small in size, simple in process, adopts a transparent electrode to construct a vertical structure, and has higher detection performance than a traditional photodetector. The photodetector can be used as an optical communication detector, integrates detection units of different bands, realizes three-channel communication, and significantly improves data capacity and transmission rate. A Bayer array model is adopted in the structure of the photodetector array, color imaging can be completed without covering a filter array on a photosensitive layer, and image information acquisition and algorithm synthesis of a color image are realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of optoelectronic devices, and particularly relates to a multi-band composite photodetector based on a Bayer model and a preparation method thereof. BACKGROUND

[0002] The photodetector has very important application value in many fields such as daily life, industrial production, aerospace and military, and has great development potential in the fields of semiconductors and chips.

[0003] At present, the photodetector type is mainly single-band detection, and it is necessary to build an optical system to construct multi-band detection, such as remote sensing and weather satellites, which has a large volume and a complex structure; in the direction of optical communication, the existing detector cannot realize composite detection, and the communication rate and data transmission capacity need to be improved; the core device of current color imaging is a charge-coupled device (CCD), which needs to cover a filter array on the photosensitive layer, and the progress is relatively slow due to the light wave diffraction effect.

[0004] Under the background of the national medium and long-term science and technology development plan and the requirements of the development trend of the detector industry, relying on multi-sensor information fusion technology, the innovative development of multi-purpose and high-performance photodetectors will become an important strategic goal. SUMMARY

[0005] Based on the current research status and the problems faced by the development trend of the photodetector, the application designs a multi-band composite photodetector based on the Bayer model. The photodetector can realize multi-band independent detection, has a small volume and a simple process; a three-channel composite communication mode can significantly improve the optical communication transmission rate and data capacity; and color imaging can be completed without covering a filter array on the photosensitive layer.

[0006] Unlike the traditional photodetector parallel structure electrode with slow response speed and low detection degree, the photodetector of the application adopts a vertical structure, and the performance is significantly improved. The vertical structure device designed in the application has a fast response speed, a high detection degree, and can realize the rapid response of weak signals. The material is synthesized by a solution method, and the device is prepared by a spin coating method, so the process is simple and practical. The photosensitive layer adopts a Bayer array model structure, and a 2x2 pixel unit is composed of visible, near-infrared and ultraviolet units.

[0007] The ultraviolet band adopts all-inorganic cesium lead-based halogen perovskite colloidal quantum dots, the visible light band adopts PMMA-doped P3HT thin film material synthesized by a solution method, and the near-infrared band adopts PbS colloidal quantum dots synthesized by a thermal injection method. The absorption spectrum lines of the three materials cover the ultraviolet, visible and near-infrared bands, and an Au / Ag nanowire network is prepared as a transparent electrode by an in-situ self-assembly solution process. Compared with ITO and FTO electrodes, the Au / Ag nanowire network has high transmittance to the ultraviolet to near-infrared band.

[0008] The technical scheme adopted by the present application to solve its technical problems is:

[0009] A preparation method of a multi-band composite photodetector based on a Bayer model, comprising the following steps:

[0010] Step S1, preparation of gold-silver nanowires

[0011] Add tetrachloroauric acid HAuCl4·4H2O to the cetyltrimethylammonium bromide CTAB solution, then add silver nitrate solution to the mixed solution, and then add sodium borohydride solution to the precursor solution to start the gold-silver reduction reaction.

[0012] After the reaction is completed, immediately drop the solution on the Si / SiO2 substrate to uniformly cover the silicon wafer substrate to form a thin film, and the gold-silver nanowires grow in the original position by self-assembly.

[0013] After the solution is volatilized, the substrate with gold-silver nanowires is placed in a water and alcohol mixed solution, and the sample with gold-silver nanowires is dried.

[0014] Step S2, preparation of CsPbCl3 colloidal quantum dots

[0015] Dissolve PbCl2 and CsCl in LDMF. Add OA and OAm to stabilize the precursor solution, and stir the mixture at room temperature until completely dissolved.

[0016] Rapidly add the precursor solution to toluene. Then centrifuge the crude colloidal solution. Then collect the precipitate and disperse it in hexane.

[0017] Step S3, preparation of PbS colloidal quantum dots

[0018] Dissolve PbO in a mixed solution of oleic acid (OA) and 1-octadecene (ODE), then heat and stir until completely dissolved to obtain a PbO-OA-ODE mixed solution, and then heat. Add methanol in a small beaker and place it in ice water.

[0019] Mix and stir hexamethydisilathiane (TMS) and 1-octadecene (ODE) to obtain a TMS-ODE mixed solution, and load it into a syringe; reduce the temperature of the PbO-OA-ODE mixed solution, and quickly inject the TMS-ODE mixed solution into the flask for heating. Perform the quenching step.

[0020] The TMS-ODE mixed solution is cleaned with an isopropanol-acetone mixed solution, the isopropanol-acetone mixed solution and the PbS quantum dot mixed solution are centrifuged, the PbS quantum dot material obtained by centrifugation is dissolved in n-hexane, and then cleaned with an isopropanol-acetone mixed solution, repeated three times and then dried, so that the solvent in the quantum dots is completely volatilized.

[0021] The dried PbS quantum dots are dissolved in n-octane and filtered with an organic filter head. Toluene solution is added to the centrifuge tube containing the precipitate, and the quantum dot solution is stored in a vial. The resulting material is centrifuged using a centrifuge, and finally PbS is extracted.

[0022] Step S4, preparation of P3HT PMMA doped thin film material

[0023] P3HT is used as the active layer, and PMMA is doped at a certain proportion to study the effect of doping on the performance of field effect transistors.

[0024] Step S5, device fabrication

[0025] The gold electrode is prepared by thermal evaporation method, and the active layer material is prepared into thin film by spin coating method. Transparent electrodes are deposited on the bottom and top layers of the device. The device preparation process is greatly simplified compared with the prior art.

[0026] In the above scheme, the water and alcohol mixed solution in step S1 is in a volume ratio of 3:7. It takes about 15 minutes to completely clean the residual CTAB on the surface of the gold-silver nanowire.

[0027] In the above scheme, the drying operation in step S1 is performed in a 50℃ vacuum drying box for 12 hours.

[0028] In the above scheme, the centrifugation time in step S2 is 5 minutes at a speed of 10000 revolutions per minute.

[0029] In the above scheme, after PbO is dissolved in the mixed solution of oleic acid and octadecene, heating and stirring are performed at 100℃ for 1.5 hours.

[0030] In the above scheme, the PbO-OA-ODE mixed solution is heated to 150℃ and kept for about 30 minutes.

[0031] In the above scheme, the temperature is reduced from 150℃ to 120℃ and kept for 10 minutes. After the TMS-ODE mixed solution is injected into the flask, heating reaction is performed for 10 minutes.

[0032] In the above scheme, the isopropyl alcohol: acetone mixed solution in step S3 is 1:1, the isopropyl alcohol-acetone mixed solution and the PbS quantum dot mixed solution are 3:1, and the mixture is loaded into a centrifugal tube for centrifugation.

[0033] In the above scheme, the drying operation in step S3 is drying in a 50℃ vacuum drying box for 10 hours to completely volatilize the solvent in the quantum dots.

[0034] In the above scheme, step S4 is specifically: P3HT is used as an active layer, and is doped with PMMA at a certain proportion. The total concentration of the solute is maintained at 10 mg / m L. The experimental group is doped with PMMA at a mass percentage of 20%, 50% and 60% in P3HT, respectively, with a pure P3HT active layer device without PMMA doping as a reference group. Chlorobenzene is selected as the solvent, and the prepared solution is fully stirred and dissolved. The prepared PVP dielectric layer is taken out without any preliminary treatment, an appropriate amount of solution is dropped on the surface, and then the active layer film with a thickness of 40 nm is obtained by spin coating. The sample is annealed.

[0035] Further, the prepared solution in step S4 is stirred for more than 10 hours to ensure that the solute is fully dissolved.

[0036] Further, the spin coating operation in step S4 is spin coating at a speed of 2000 rpm for 30 seconds.

[0037] Further, the annealing operation in step S4 is annealing at 120℃ in an inert atmosphere for 5 minutes and cooling to room temperature.

[0038] In the above scheme, step S5 is specifically: Figure 4 vacuum evaporation of gold electrodes on the cleaned substrate, bonding of a layer of polyimide film, deposition of a bottom layer of Au / Ag nanowire transparent electrode, use of a Bayer array model structure for the photosensitive layer, 2x2 pixel units composed of visible, near-infrared and ultraviolet units, spin coating of photoactive materials, and deposition of a top layer of Au / Ag nanowire transparent electrode.

[0039] A multi-band composite photodetector based on a Bayer model, which is prepared by the preparation method of the multi-band composite photodetector based on the Bayer model.

[0040] The beneficial effects of the present application are:

[0041] The application realizes independent detection and signal combination of ultraviolet, visible and near-infrared bands, adopts a transparent electrode to construct a vertical structure, and has higher detection performance than a traditional photodetector. The application can be used as an optical communication detector, integrates detection units of different bands, realizes three-channel communication, the maximum optical responsivity of the device is about 9*10^2 A / W, the normalized detection degree of the device is as high as 7*10^12 Jones, and the data capacity and transmission rate are improved by three times compared with a traditional photodetector. The detector array structure adopts a Bayer array model, realizes image information acquisition and algorithm synthesis of a color image, and can realize color imaging without a filter array. BRIEF DESCRIPTION OF DRAWINGS

[0042] Fig. 1(a) is a schematic diagram of a synthesis process of a gold-silver nanowire solution according to an embodiment of the application, and Fig. 1(b) is a diagram of an experimental device for preparing Pbs quantum dots.

[0043] Figure 2 Fig. 2 is a SEM image and an absorption spectrum of three materials according to an embodiment of the application. Among them Figure 2 (a) is a perovskite (CsPbCl3) material, Figure 2 (b) is a P3HT material, Figure 2 (c) is a pbs quantum dot material, Figure 2 (d) is an absorption spectrum of the three materials.

[0044] Figure 3 Fig. 3 is an Au / Ag nanowire transparent electrode material and its high transmittance in a full wave band according to an embodiment of the application.

[0045] Figure 4 Fig. 4 is a flow chart of device preparation according to an embodiment of the application.

[0046] Fig. 5(a) is a device structure diagram according to an embodiment of the application, Fig. 5(b) is a prototype diagram according to an embodiment of the application, Fig. 5(c) is a Bayer array electrode structure diagram, and Fig. 5(d) is a Bayer array light active layer structure.

[0047] Figure 6 Fig. 6 is an output and transfer characteristic curve of a multi-band performance test according to an embodiment of the application, and the gate has high performance control.

[0048] Figure 7 Fig. 7 is a light responsivity, photoelectric current responsivity and normalized detection degree curve of a multi-band detection performance test according to an embodiment of the application, and the device has high light responsivity and detection degree and fast response time.

[0049] Figure 8 Fig. 8 is a three-signal communication function according to an embodiment of the application.

[0050] Figure 9Color imaging function of an embodiment of the present application. DETAILED DESCRIPTION

[0051] The present application will be further described with reference to the accompanying drawings and examples, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The examples described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0052] As shown in Fig. 5(a), the full-inorganic cesium-lead-based halogen perovskite colloidal quantum dots 1, the PMMA-doped P3HT thin film material 2, the PbS colloidal quantum dots 3, the Au / Ag nanowire mesh transparent electrode 4, the gold electrode 5, the polyimide thin film 6, the silicon dioxide substrate 7, and the silicon substrate 8.

[0053] As shown in Fig. 5(d), the multi-band composite photodetector based on the Bayer model provided in the present embodiment has a 4x4 Bayer array model structure for the photosensitive layer. The 2x2 pixel unit is composed of visible, near-infrared, and ultraviolet photosensitive units.

[0054] In the present embodiment, the center point distance between any two of the light active material points 1, 2, and 3 is 3 mm, and the diameter of each point is 3 mm. The pin 9 is 2 cm long, the substrates 7 and 8 are silicon wafers with a size of 2.5 cm x 2.5 cm, and the gold electrodes 5 are arranged as shown in Fig. 5(c). The width of each electrode is 3 mm, and the center point distance between any two electrodes in the same direction is 3 mm.

[0055] It is worth noting that in the present embodiment, each structure can be adjusted to have a different center distance according to the same principle and structure, in combination with the actual size of the substrates 7 and 8.

[0056] The method for preparing the multi-band composite photodetector based on the Bayer model first prepares three kinds of light active materials CsPbCl, P3HT, PbS, and gold-silver nanowires. Then, the light active materials are spin-coated and the gold-silver nanowire transparent electrode is deposited using the Bayer array structure. As shown in Fig. 5(d), the multi-band composite photodetector based on the Bayer model has a 4x4 Bayer array model structure for the photosensitive layer. The 2x2 pixel unit is composed of visible, near-infrared, and ultraviolet photosensitive units. Figures 1(a)-9 The specific embodiment of the present application includes the following steps:

[0057] I. Preparation of light active materials and gold-silver nanowires

[0058] Step S1, preparation of gold-silver nanowires

[0059] Chemical reagents required for the synthesis of gold-silver nanowires: cetyltrimethylammonium bromide (CTAB), chloroauric acid (S, purity 90%), sodium ascorbate (OLA, purity 90%), silver nitrate (analytical pure), sodium borohydride, ethanol (analytical pure).

[0060] Experimental apparatus: several beakers, temperature controller, pipette, glass bottles, vacuum drying oven, etc. The synthesis process of gold and silver nanowire solution is shown in Figure 1(a).

[0061] (1) Weigh hexadecyltrimethylammonium bromide (CTAB) and place it in a beaker containing deionized water in a 35°C water bath. Use a magnetic stirrer to completely dissolve CTAB to form a colorless and transparent CTAB solution.

[0062] (2) When the chloroauric acid solution is added to the CTAB solution using a pipette, the mixture of CTAB and chloroauric acid solution turns light yellow.

[0063] (3) 100 μL of silver nitrate solution was added to the light yellow mixed solution, and the solution color did not change.

[0064] (4) To further reduce monovalent gold ions to metallic gold, an additional catalyst, sodium borohydride solution containing gold seed particles, is needed. Therefore, the transferred sodium borohydride solution is added to a colorless precursor solution to begin the gold-silver reduction reaction.

[0065] (5) After the reaction is complete, immediately remove the solution droplet from the 1.4cm×1.4cm Si / SiO2 substrate that has been placed in a 500ml beaker, so that the solution can uniformly cover the silicon substrate to form a thin film. Maintain an environment of about 35°C and a relative humidity of ~50% to allow the reaction solution to evaporate and dry naturally. At this time, the gold and silver nanowires will grow by self-assembly in their original positions.

[0066] (6) After the solution has evaporated, place the substrate with gold and silver nanowires into a water and alcohol mixture prepared in a volume ratio of 3:7 to thoroughly clean the residual CTAB on the surface of the gold and silver nanowires. This takes about 15 minutes.

[0067] (7) Place the sample with gold and silver nanowires in a vacuum drying oven at 50°C and dry for 12 hours.

[0068] Au / Ag nanowire transparent electrode materials and their high transmittance across the entire wavelength range, such as Figure 3 As shown.

[0069] Step S2, Preparation of CsPbCl

[0070] (1) Dissolve LDMF in 10 mL of PbCl2 (0.4 mmol, 0.1468 g) and CsCl (0.4 mmol, 0.0851 g). Add OA (1 mL) and OAm (0.5 mL) to stabilize the precursor solution, and stir the mixture at room temperature until completely dissolved.

[0071] (2) 2 ml of the precursor solution was quickly added to 10 mL of toluene. Immediately after injection, the colorless solution was observed to turn green. After 10 s, the crude colloidal solution was centrifuged at 10,000 rpm for 5 min. The precipitate was then collected and dispersed in hexane.

[0072] A scanning electron microscope (SEM) image of the perovskite (CsPbCl3) material is shown in FIG. 2(a). Figure 2 (a).

[0073] Step S3, Preparation of PbS quantum dots

[0074] Experimental apparatus: magnetic stirrer (iron rod, fixed frame), heating jacket, three-necked flask (25 ml), thermometer, condenser, exhaust device, rubber bulb pipette (glass), several rubber tubes, magnetic sub (pay attention to the size, which is very important for the experiment). The experimental apparatus is shown in FIG. 1(b).

[0075] (1) Dissolve PbO in a mixed solution of oleic acid (OA) and 1-octadecene (ODE), and then heat and stir at 100°C for 1.5 hours,

[0076] (2) Wait until complete dissolution to obtain a PbO-OA-ODE mixed solution, and then heat to 150°C for about 30 minutes;

[0077] (3) Add methanol in a small beaker and place it in ice water.

[0078] (4) Mix and stir hexamethydisilathiane (TMS) and 1-octadecene (ODE) to obtain a TMS-ODE mixed solution, and load it into a syringe;

[0079] (5) Reduce the temperature of the PbO-OA-ODE mixed solution from 150°C to 120°C and maintain for 10 minutes, quickly inject the TMS-ODE mixed solution into the flask, heat and react for 10 minutes, and then remove the heating device;

[0080] (6) Perform the quenching step.

[0081] (7) Wash the mixed solution in step 4 with a mixed solution of isopropyl alcohol: acetone = 1:1, take 3 volumes of the isopropyl alcohol-acetone mixed solution and 1 volume of the PbS quantum dot mixed solution, load them into a centrifuge tube for centrifugation, dissolve the PbS quantum dot material obtained by centrifugation with n-hexane, and then wash it with the isopropyl alcohol-acetone mixed solution, repeat three times, and place it in a 50°C vacuum drying oven for 10 hours to completely volatilize the solvent in the quantum dots.

[0082] (8) The dried PbS quantum dots are dissolved in n-octane with a concentration of 50 mg / mL, filtered with a 0.45 um organic filter head, and stored in a glove box for later use.

[0083] The toluene solution is added to the centrifuge tube containing the precipitate, and the quantum dot solution is stored in a vial and labeled.

[0084] During the experiment, attention should be paid to checking whether the magnetic sub is rotating, whether the ventilation is working, and whether the water circulation is working.

[0085] The resulting material is centrifuged using a centrifuge (8000 n / s) to wash it, and the desired PbS is finally extracted.

[0086] Methanol - centrifugal precipitate (retained)

[0087] n-hexane - centrifugal solution (retained)

[0088] The SEM image of the PbS quantum dot material is as shown in Figure 2 (c).

[0089] Step S4, preparation of P3HT PMMA doped material

[0090] P3HT is used as the active layer, and a certain proportion of PMMA is used to dope it, and the effect of doping on the performance of the field effect transistor is studied. The total concentration of the solute is maintained at 10 mg / m L, and the pure P3HT active layer device without PMMA doping is used as the reference group, and the experimental group is doped with P3HT at a mass percentage of 20%, 50%, and 60% of PMMA. Chlorobenzene is selected as the solvent, and the prepared solution is stirred for more than 10 h to ensure that the solute is fully dissolved. The prepared PVP dielectric layer is taken out without any preliminary treatment, and an appropriate amount of solution is dropped on its surface, and a 40 nm thick active layer film is obtained by spin coating at a speed of 2000 rpm for 30 s. The sample is placed in an inert atmosphere and annealed at 120°C for 5 min, and then cooled to room temperature. The SEM image of the P3HT material is as shown in Figure 2 (b).

[0091] II. Device preparation

[0092] Unlike the traditional photodetector parallel structure electrodes, the present application adopts a vertical structure, and the performance is significantly improved. The material is synthesized by a solution method, and the device is prepared by a spin coating method, and the process is greatly simplified. The device manufacturing process is as follows Figure 4As shown, first vacuum evaporate gold electrode on the cleaned substrate, then bond a layer of polyimide film, and then deposit the bottom layer of gold-silver nanowire transparent electrode, the photosensitive layer adopts the Bayer array model structure, the visible, near-infrared and ultraviolet units constitute a 2x2 pixel unit, respectively spin-coat the photoactive material, and finally deposit the top layer of gold-silver nanowire transparent electrode. The device preparation process is greatly simplified. The positions of various materials are as shown in Figures 5(a)-5(d) .

[0093] The present application realizes independent detection of ultraviolet, visible and near-infrared bands and signal composition; realizes three-signal communication, and significantly improves information transmission rate and data capacity; realizes image information acquisition and algorithm synthesis of color image. The multi-band detection-output and transfer characteristics are as shown in Figure 6 , the signal acquisition uses Keithley 2400 digital source meter and HP6030A DC power supply, common source test, and labview electrical performance test software for data processing. The device exhibits bipolar output characteristics and high-performance gate control characteristics. The multi-band detection-optoelectronic performance is as shown in Figure 7 , the optoelectronic performance test uses Keithley 2400 digital source meter and optical chopper, and the laser wavelengths are 405nm, 532nm and 808nm in turn. The device performance parameters are obtained through formula calculation and data processing. Compared with traditional photodetectors, it has high light response and detection degree, and fast response time. The three-channel communication function is as shown in Figure 8 , the photodetector is the core device of the receiving module in optical communication, which plays the role of converting optical signals into electrical signals. The lasers with wavelengths of 405nm, 532nm and 808nm are used as three-way emission sources, the signals of the photodetector are collected by the digital source meter through relay control, and the results are displayed in the labview program. The data capacity and transmission rate of the optical communication system are significantly improved compared with single channel. The color imaging function is as shown in Fig. 9, the light emitted by the light source passes through the mask plate and is imaged on the photodetector, four detector units constitute a pixel, and the information collected by the Bayer array is obtained after algorithm demosaicing and image processing. Compared with traditional array photodetectors, not only image information can be obtained, but also color information can be obtained. Compared with color sensors, the filter array is removed, and the device cost is reduced. For remote sensing detection, visible light communication and hyperspectral imaging fields have important application value. Different band detector units are combined into a detection array, and the detection signals are read by band; through the integration of different detection units, the communication mode is expanded from single channel to three-signal communication; the Bayer array model is used to construct the array detector, which can realize color imaging without filter array.

[0094] It should be understood that although the present specification is described in terms of various embodiments, not every embodiment need necessarily include every independent technique described herein, and description of a particular feature or technique in terms of an other feature or technique that has already been described should not automatically be interpreted as meaning that every embodiment must necessarily include both the particular feature and the other feature or technique. Rather, the specification is intended to be read as a whole, and the features and techniques described herein can be combined and rearranged in a variety of ways, and the various embodiments can be combined to form other embodiments.

[0095] The above detailed description of a series of specific embodiments is merely intended to illustrate the feasibility of the present application, and is not intended to limit the protection scope of the present application. Any equivalent means or changes that do not deviate from the technical spirit of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a multi-band composite photodetector based on a Bayer model, characterized in that, Comprising: S1, preparing gold and silver nanowires; Add chloroauric acid tetrahydrate HAuCl4·4H2O into the cetyltrimethylammonium bromide CTAB solution, then add silver nitrate solution into the mixed solution, and then add sodium borohydride solution into the precursor solution to start the reduction reaction of gold and silver; After the reaction is completed, immediately remove the solution and drop it on the Si / SiO2 substrate to make the solution evenly cover the silicon substrate to form a thin film, and the gold and silver nanowires grow in the original position by self-assembly; After the solution is volatilized, the substrate with the grown gold and silver nanowires is placed in a water and alcohol mixed solution, and the sample with the grown gold and silver nanowires is dried; S2, preparing CsPbCl3 colloidal quantum dots; Dissolve PbCl2 and CsCl in LDMF, add OA and OAm to stabilize the precursor solution, and stir the mixture at room temperature until it is completely dissolved; Quickly add the precursor solution into toluene, then centrifuge the crude colloidal solution, collect the precipitate and disperse it in hexane; S3, preparing PbS colloidal quantum dots; Dissolve PbO in a mixed solution of oleic acid (OA) and 1-octadecene (ODE), then heat and stir until completely dissolved to obtain a PbO-OA-ODE mixed solution, then heat, add methanol in a small beaker and place it in ice water; Mix and stir hexamethydisilathiane (TMS) and 1-octadecene (ODE) to obtain a TMS-ODE mixed solution, and load it into a syringe; reduce the temperature of the PbO-OA-ODE mixed solution, quickly inject the TMS-ODE mixed solution into the flask and heat to quench; Wash the TMS-ODE mixed solution with an isopropanol-acetone mixed solution, centrifuge the isopropanol-acetone mixed solution and the PbS quantum dot mixed solution, dissolve the obtained PbS quantum dot material with n-hexane, then wash it with an isopropanol-acetone mixed solution, repeat three times and then dry to completely volatilize the solvent in the quantum dots; Dissolve the dried PbS quantum dots in n-octane and filter with an organic filter head, add toluene solution to the centrifuge tube containing the precipitate, store the quantum dot solution in a vial, use a centrifuge to centrifuge and wash the obtained material, and finally extract the PbS; S4, preparing a PMMA-doped P3HT solution; The specific process of step S4 includes: using P3HT as the active layer and doping it with PMMA, keeping the total concentration of solute at 10 mg / m L, and doping P3HT with PMMA at mass percentages of 20%, 50%, and 60%, respectively; S5, making a device The specific process of S5 includes: First, vacuum evaporation of gold electrode on the cleaned substrate; then bonded a layer of polyimide film; then deposited Au / Ag nanowire transparent electrode; the photosensitive layer adopts the Bayer array model structure, visible, near-infrared and ultraviolet unit constitute 2 by 2 pixel unit, respectively, spin CsPbCl3 colloidal quantum dots light active material, PbS colloidal quantum dots light active material and PMMA doped P3HT solution; finally, deposition of top Au / Ag nanowire transparent electrode.

2. The method for preparing a multi-band composite photodetector based on the Bayer model according to claim 1, characterized in that, In the step S1, the water and alcohol mixed solution is in a volume ratio of 3:7, which is used to clean the residual CTAB on the surface of gold and silver nanowires for 15 minutes; The drying operation is performed in a 50℃ vacuum drying oven for 12 hours.

3. The method of claim 1, wherein the method further comprises: In the step S2, the centrifugation operation time is 5 minutes, and the rotation speed is 10000 revolutions per minute.

4. The method of claim 1, wherein the method further comprises: In the step S3, after PbO is dissolved in the mixed solution of oleic acid and octadecene, heating and stirring are performed at 100℃ for 1.5 hours; The PbO-OA-ODE mixed solution is heated to 150℃ and kept for about 30 minutes; The temperature of the PbO-OA-ODE mixed solution is reduced from 150℃ to 120℃ and kept for 10 minutes. After the TMS-ODE mixed solution is injected into the flask, heating reaction is performed for 10 minutes; The drying operation is performed in a 50℃ vacuum drying oven for 10 hours to completely volatilize the solvent in the quantum dots, The isopropyl alcohol:acetone mixed solution is 1:1, and the volume of the isopropyl alcohol-acetone mixed solution is 3, and the volume of the PbS quantum dot mixed solution is 1, which is loaded into a centrifuge tube for centrifugation.

5. The method for preparing a multi-band composite photodetector based on the Bayer model according to claim 4, characterized in that, The rotation speed of the centrifugation operation is 8000 revolutions per second.

6. The method of claim 1, wherein the method further comprises: In the step S4, the prepared solution is stirred for more than 10 hours to ensure that the solute is fully dissolved.

7. The method for fabricating a multi-band composite photodetector based on the Bayer model according to claim 1, characterized in that, The spin coating operation is performed at a rotation speed of 2000rpm for 30s.

8. A multi-band composite photodetector based on Bayer model, characterized in that, Obtained by the preparation method of any one of claims 1-7. Obtained by the preparation method of any one of claims 1-7.

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